Pope resigning: Historian Jon M. Sweeney shares the story behind the last pope who quit

It was strange. I write about that in the book: Isn't it interesting that the current pope feels an affinity toward Celestine V?

Q: When he became pope, Benedict said this: "Pray for me that I may not flee for fear of the wolves." You write that it's impossible to think of those words without recalling Celestine, who made a similar reference. What binds the two of them?

A: For Celestine, it's a reference to all the nonsense you have to deal with as a pope – the papal curiae and the bureaucratic mess. Somebody who probably didn't want the job in the first place, like Benedict, would have said, "Pray for me as I go in among the wolves."

Q: What sets these two popes apart from each other?

A: There are a lot of differences between the two. Celestine's papacy was a disaster, and he was completely unsuited for the life and the role of the pope. He was just a hermit who wanted to pray in the mountains.

By contrast, Benedict was an insider. Those are big differences.

Yet there are similarities, too. Neither man seemed to be very interested in the administrative aspects of the job. Being a pope is like being a huge bureaucratic manager. Celestine was inept by most accounts, and Benedict certainly showed a lack of interest in that aspect.

And both men resigned with a very simple notice that was read aloud to a group of cardinals, priests and officials who were told not to ask questions. Benedict simply announced it and just walked away. That's what Celestine did, too.

Q: We know that popes die in office or, in centuries past, were killed. Can they be fired?